/*
 * Copyright (C) 2016 - Niklas Baudy, Ruben Gees, Mario Đanić and contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.vanniktech.emoji.inputfilters

import android.text.InputFilter
import android.text.Spanned
import com.vanniktech.emoji.emojiInformation

/** Input Filter that accepts only a certain number of Emojis.  */
class MaximalNumberOfEmojisInputFilter(
  private val maxCount: Int,
) : InputFilter {
  override fun filter(source: CharSequence, start: Int, end: Int, dest: Spanned, dstart: Int, dend: Int): CharSequence? {
    val emojiInformation = dest.subSequence(0, dest.length).emojiInformation()
    return when {
      emojiInformation.emojiCount >= maxCount -> "" // Reject.
      else -> null
    }
  }
}
